Removing style from selected text in edittext

2020-03-03 09:47发布

My app should allow users to style inputted or selected text in an Edittext. Some of these styles are Underline, Strike through, Bold and Italic. They are easily added but I don't know how they could be removed and how I could determine if that style has already been added to the selected text. Code for adding style:

Spannable str = myEditText.getText();
    if (!SpannableUtils.isEmpty(str)) {
        str.setSpan(new StrikethroughSpan(), startSelection, endSelection,
                Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
    }

I tried using removeSpan but it didn't work. Also tried using

        str.setSpan(new StyleSpan(android.graphics.Typeface.DEFAULT),
                startSelection, endSelection,
                Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

but it poses the error : The constructor StyleSpan(Typeface) is undefined.

3条回答
仙女界的扛把子
2楼-- · 2020-03-03 10:02

I think this class solve your problem.

public class StyleSpanRemover {

    public void RemoveOne(Spannable spannable,
                          int startSelection, int endSelection, Class<?> style){

        ArrayList<SpanParts> spansParts = getSpanParts(spannable, startSelection, endSelection);
        removeOneSpan(spannable, startSelection, endSelection, style);
        restoreSpans(spannable, spansParts);
    }

    public void RemoveStyle(Spannable spannable,
              int startSelection, int endSelection, int styleToRemove){

        ArrayList<SpanParts> spansParts = getSpanParts(spannable, startSelection, endSelection);
        removeStyleSpan(spannable, startSelection, endSelection, styleToRemove);
        restoreSpans(spannable, spansParts);
    }

    public void RemoveAll(Spannable spannable, int startSelection, int endSelection){

        ArrayList<SpanParts> spansParts = getSpanParts(spannable, startSelection, endSelection);
        removeAllSpans(spannable, startSelection, endSelection);
        restoreSpans(spannable, spansParts);
    }

    protected void restoreSpans(Spannable spannable, ArrayList<SpanParts> spansParts){

        for (SpanParts spanParts : spansParts) {
            if(spanParts.part1.canAplly())
                spannable.setSpan(spanParts.part1.span, spanParts.part1.start,
                                  spanParts.part1.end,spanParts.span_flag);
            if(spanParts.part2.canAplly())
                spannable.setSpan(spanParts.part2.span, spanParts.part2.start,
                                  spanParts.part2.end, spanParts.span_flag);
        }
    }

    protected void removeAllSpans(Spannable spannable,int startSelection, int endSelection) {

        Object spansToRemove[] = spannable.getSpans(startSelection, endSelection, Object.class);
        for(Object span: spansToRemove){
            if(span instanceof CharacterStyle)
                spannable.removeSpan(span);
        }
    }

    protected void removeOneSpan(Spannable spannable,int startSelection, int endSelection,
                           Class<?> style) {

        CharacterStyle spansToRemove[] = spannable.getSpans(startSelection, endSelection, CharacterStyle.class);
        for(CharacterStyle span: spansToRemove){
            if(span.getUnderlying().getClass() == style )
                spannable.removeSpan(span);
        }
    }

    protected void removeStyleSpan(Spannable spannable, int startSelection,
        int endSelection, int styleToRemove) {

        MetricAffectingSpan spans[] = spannable.getSpans(startSelection, endSelection, MetricAffectingSpan.class);
        for(MetricAffectingSpan span: spans){
            int stylesApplied = 0;  
            int stylesToApply;
            int spanStart;
            int spanEnd;
            int spanFlag;
            Object spanUnd = span.getUnderlying();
            if(spanUnd instanceof StyleSpan){
                spanFlag = spannable.getSpanFlags(spanUnd);
                stylesApplied = ((StyleSpan) spanUnd).getStyle();
                stylesToApply = stylesApplied & ~styleToRemove;

                spanStart = spannable.getSpanStart(span);
                spanEnd = spannable.getSpanEnd(span);
                if(spanEnd >= 0 && spanStart >= 0){
                    spannable.removeSpan(span);
                    spannable.setSpan(new StyleSpan(stylesToApply), spanStart, spanEnd,spanFlag);
                }
            }
        }
    }

    protected ArrayList<SpanParts> getSpanParts(Spannable spannable,
                                              int startSelection,int endSelection){

        ArrayList<SpanParts> spansParts = new ArrayList<SpanParts>();
        Object spans[] = spannable.getSpans(startSelection, endSelection, Object.class);
        for(Object span: spans){
            if(span instanceof CharacterStyle){
                SpanParts spanParts = new SpanParts();
                int spanStart = spannable.getSpanStart(span);
                int spanEnd = spannable.getSpanEnd(span);
                if(spanStart == startSelection && spanEnd == endSelection) continue;
                spanParts.span_flag = spannable.getSpanFlags(span);
                spanParts.part1.span = CharacterStyle.wrap((CharacterStyle) span);
                spanParts.part1.start = spanStart;
                spanParts.part1.end = startSelection;
                spanParts.part2.span = CharacterStyle.wrap((CharacterStyle) span);
                spanParts.part2.start = endSelection;
                spanParts.part2.end = spanEnd;
                spansParts.add(spanParts);
            }
        }
        return spansParts;
    }

    private class SpanParts{
        int span_flag;
        Part part1;
        Part part2;
        SpanParts() {
            part1 = new Part();
            part2 = new Part();
        }
    }
    private class Part{
        CharacterStyle span;
        int start;
        int end;
        boolean canAplly() {
            return start < end;
        }
    }
}

How to use:

int startSelection=editText.getSelectionStart();
int endSelection=editText.getSelectionEnd();
Spannable spannable = editText.getText();

StyleSpanRemover spanRemover = new StyleSpanRemover();
// to remove all styles
spanRemover.RemoveAll(spannable,startSelection,endSelection);
//to remove only StrikethroughSpan style use:
spanRemover.RemoveOne(spannable,startSelection,endSelection,StrikethroughSpan.class);
//to remove one StyleSpan use:
spanRemover.RemoveStyle(spannable,startSelection,endSelection,Typeface.BOLD)
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干净又极端
3楼-- · 2020-03-03 10:06

android.graphics.TYPEFACE.Default returns a Typeface, and the StyleSpan constructor takes an int as paramater.

Try using :

android.graphics.Typeface.DEFAULT.getStyle() 

instead of:

android.graphics.Typeface.DEFAULT
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姐就是有狂的资本
4楼-- · 2020-03-03 10:15

I think this way below is the simplest but useful. It works for me.

Please try this code:

myEditText.setTypeface(Typeface.DEFAULT);
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